1. Field of the Invention
The present invention relates to a connector which, when performing electrical wiring, is used to establish a male-female union at ends of the electrical wires and, more particularly, to such a connector provided with a water-resistant structure wherein current will not leak between respective terminal fixtures.
2. Description of the Related Art
In a connector assembly including male and female connectors each provided with a plurality of cavities, when a potential difference occurs between terminal fixtures within adjacent cavities while the connector is wet, current flows (referred to as "leakage current") between the two terminal fixtures. When leakage current flows, the terminal fixtures may corrode (i.e., electrical corrosion), and so various water-resistant structures have been considered in the prior art in order to prevent this problem.
These structures include a completely water-resistant structure and a simplified water-resistant structure.
FIG. 5 is a sectional view of a connector implementing a completely water-resistant structure.
A rubber plug 2 and insulated electrical wire 3 are crimped by the rear end of a male terminal fixture 1. The male terminal fixture 1 is inserted into a cavity 6 formed in a housing 5 of a male connector 4. The housing 5 is formed with a plurality of parallel cavities 6, and respective open ends of the cavities are sealed by the rubber plug.
Further, a hood 8, which receives a mating connector 7, is formed at the other end of the housing 5. An annular seal 9 is disposed in a space within the hood 8. When the mating connector 7 is housed within the hood 8, the annular seal 9 is interposed between the inner peripheral surface of the hood 8 and the outer peripheral surface of the mating connector 7 to provide resistance to water.
Although complete water resistance can be expected if a rubber plug 2 and seal 9 are used in this manner, the rubber plug 2 and seal 9 contribute to a comparatively high cost of the assembly, and the operation of passing the insulated electrical wire 3 through the rubber plug 2 is troublesome. Because of this, a simpler water-resistant structure is employed, for example, in the upper areas of an engine compartment of an automobile and similar locations where the chance of water penetration is small.
Japanese Laid-Open Utility Model Application No. 56-57486 discloses such a known simplified water-resistant structure.
An end of a connector housing wherein a terminal fixture is inserted in a cavity is formed with a groove provided between adjoining ones of such cavities. As a result of the provision of such a groove, a path of least resistance between the two cavities traverses the groove, thereby impeding leakage current between the cavities.
One of the connectors is provided with a hood in the form of a double frame comprising an inner frame and outer frame. The other connector is provided with a hood in the form of a single frame insertable within the clearance between the inner and outer frames. When the respective hoods are brought together and the single hood is inserted into and mated with the double hood, it is difficult for water to penetrate past the mating portions of connectors, and so the generation of leakage current between cavities within the connectors is prevented.
However, the connector assembly having the above-described simplified water-resistant structure has the following problems.
Because a groove is formed between the cavities water may penetrate into the groove, i.e. it is possible for the interior of the groove to become submerged in water. In such a case, a large leakage current can flow between the cavities and the electrical corrosion of the terminal fixtures cannot be prevented.
Furthermore, with regard to the mating portions of the male and female connectors, three layers of hoods overlap, and so the external dimensions of the mating portions are necessarily large and the overall size of the connector assembly is correspondingly comparatively large.